greentest: execute cleanup() if present

--HG--
extra : transplant_source : %F0%EC%09%289%E9w%E4F%02/Z%2Cz%A5G%28%C6%40%3B

greentest/greentest.py

@@ -59,6 +59,8 @@ class TestCase(BaseTestCase):
         self._timer = gevent.Timeout.start_new(self.__timeout__, RuntimeError('test is taking too long'))
 
     def tearDown(self):
+        if hasattr(self, 'cleanup'):
+            self.cleanup()
         try:
             if not hasattr(self, 'stderr'):
                 self.unhook_stderr()